Reference mirror converter of Linnik interferometer

Abstract

Provided is a reference mirror converter of a Linnik interferometer in which a first object lens 30 focuses light emitted from a beam splitter 20 on a reference mirror 40 , a plurality of reference mirrors 40 reflects light incident from the first object lens 30 , a plurality of reference mirrors 40 is disposed on a plurality of reference mirror brackets 45 , respectively, the plurality of reference mirror brackets 45 is disposed on a rotary plate 60 at the same angles, and the rotary plate 60 is rotated using a motor 70 to control a rotation of the rotary plate 60 to select the reference mirror 40 having a reflectivity similar to that of a target 200 to be measured from among the plurality of reference mirrors 40 . Accordingly, since a separate state between articles is maintained at all times, adhesiveness between articles packaged with an easily adhesive material may be prevented.

What is claimed is: 
     
       1. A reference interferometer comprising:
 a second object lens magnifying an image of a target object into a first image; 
 a camera capturing the first image; 
 a beam splitter directing a portion of a first light irradiated from a light source or a portion of a second light emitted from the second object lens to the camera and to one of a plurality of reference mirrors by penetrating or reflecting; 
 a first object lens focusing a third light emitted from the beam splitter on the one of the plurality of reference mirrors, 
 wherein the plurality of reference mirrors reflect the third light incident from the first object lens; 
 a plurality of reference mirror brackets supporting the plurality of reference mirrors, respectively, wherein each of the plurality of reference mirror brackets is disposed at a rotary plate and has a substantially same central angle with respect to a center of the rotary plate; 
 a motor generating a rotational force to the rotary plate; 
 an initial rotation angle sensor sensing an initial rotation angle of the rotary plate; and 
 a control device rotating the rotary plate by controlling the motor in response to a command of a user, sensing an initial rotation angle using the initial rotation angle sensor, and controlling a rotation of the rotary plate to select at least one of the plurality of reference mirrors. 
 
     
     
       2. The reference interferometer of  claim 1 , wherein the rotary plate has a plurality of bracket holes to accommodate the plurality of reference mirror brackets, respectively, and
 wherein a portion of the plurality of bracket holes are blocked to shield the third light incident from the first object lens instead of reflecting the third light, enabling a two-dimensional (2D) measurement. 
 
     
     
       3. The reference interferometer of  claim 2 , wherein a front surface of at least one of the plurality of reference mirror brackets has a focus adjust groove to traverse a center thereof, and
 the at least one of the plurality of reference mirror brackets moves forward or backward to adjust an optical path of the first object lens and an optical path of the second object lens to match one another. 
 
     
     
       4. The reference mirror converter of  claim 2 , wherein a plurality of tilting adjust screws are disposed at preset angles along the circumference of each of the plurality of reference mirror brackets to adjust an optical path of the first object lens and an optical path of the second object lens to match with respect to the third light incident from the first object lens, and to adjust a central optical axis of the first object lens normal to a reference mirror plane. 
     
     
       5. The reference interferometer of  claim 1 , wherein a front surface of at least one of the plurality of reference mirror brackets has a focus adjust groove to traverse a center thereof, and
 the at least one of the plurality of reference mirror brackets moves forward or backward to adjust an optical path of the first object lens and an optical path of the second object lens to match one another by. 
 
     
     
       6. The reference interferometer of  claim 1 , wherein a plurality of tilting adjust screws are disposed at preset angles along the circumference of each of the plurality of reference mirror brackets to adjust an optical path of the first object lens and an optical path of the second object lens to match with respect to the third light incident from the first object lens, and to adjust a central optical axis of the first object lens normal to a reference mirror plane. 
     
     
       7. The reference interferometer of  claim 6 , wherein a reference mirror bracket fastener is disposed at a location corresponding to each of the plurality of reference mirror brackets on the side of the rotary plate to fasten each of the plurality of reference mirror brackets in a tilting-adjusted state and in a state in which the optical path of the first object lens and the optical path of the second object lens are adjusted to match. 
     
     
       8. The reference interferometer of  claim 7 , wherein the reference mirror bracket fastener fastens a bracket set screw by forming a set screw hole along the side of the rotary plate and by disposing a fastener of synthetic resin.